Seriously?
Galatians 2
14 But when I saw that they were not straightforward about the truth of the gospel, I said to Peter before them all, “If you, being a Jew, live in the manner of Gentiles and not as the Jews, why do you compel Gentiles to live as Jews?
Earlier he says that Peter ate with the Gentiles. He ate with these formerly unclean people and their unclean food categorized as such under the old law.
And what did Paul understand about the old law? That it was dead.
Colossians 2
11 In Him you were also circumcised with the circumcision made without hands, by putting off the body of the sins of the flesh, by the circumcision of Christ, 12 buried with Him in baptism, in which you also were raised with Him through faith in the working of God, who raised Him from the dead. 13 And you, being dead in your trespasses and the uncircumcision of your flesh, He has made alive together with Him, having forgiven you all trespasses, 14 having wiped out the handwriting of requirements that was against us, which was contrary to us. And He has taken it out of the way, having nailed it to the cross. 15 Having disarmed principalities and powers, He made a public spectacle of them, triumphing over them in it.
As he also explains in Hebrews, going back to the law also means sacrificing animals for sin remission and that is actually an insult against Jesus who made the ultimate sacrifice "once for all."
You can't go back to the law of Moses and just satisfy some of its requirements. You would theoretically have to obey ALL of its requirements. Though after AD 70 it is impossible to obey that law since there is no more a Levitical priesthood and there isn't a temple for offering those sacrifices.